I'd do 9x4=36 because the 9 is from your money and the 4 is from your books. Now since you want to find out how much 4 books cost you just multiply that by 9
The first box is 3 more than the quotient of 6 and a number, the second is 6 less than the product of 3 and a number, the third box is the product of 6 and the sum of a number and 3.
